JSFiddle - React, Tailwind, and code Playground
HTML
<input type='text' id='valorInput' name='valor'>
<div id='valor'><b>R$ 1,00</b></div>
JavaScript
$(document).ready(function() {
$('#valorInput').on('change', function() {
var value = $(this).val();
$('#valor b').text('R$ '+value);
})
})